1. Technical Field
The present invention relates to an electrooptical device substrate and a method for manufacturing the same, an electrooptical device, and an electronic apparatus.
2. Related Art
Mentioned as this kind of the electrooptical device substrate is, for example, one having an organic thin film transistor (hereinafter referred to as an “organic TFT (Thin Film Transistor)” as appropriate) on a support substrate, such as a plastic substrate. As a method for manufacturing such an electrooptical device substrate, a technique for forming thin film layers, such as an organic semiconductor layer and a gate electrode, which constitute the organic TFT, by, for example, a printing method, such as a liquid droplet ejecting method is known, for example.
For example, JP-A-2004-87976 discloses a technique including irradiating a base layer of a conductive layer to be formed, i.e., a photocatalyst containing layer, with ultraviolet rays through a photomask, thereby forming a region having lyophilicity to a conductive layer material liquid and a region having liquid repellency to the conductive layer material on the base layer. Moreover, a technique including irradiating only a region, which needs to be rendered lyophilic, with laser light instead of the exposure through a photomask is also disclosed.
JP-A-2006-237477 discloses a technique of utilizing an interlayer insulating film on a gate insulating film as a partition for forming a gate electrode using a liquid droplet ejecting method.
However, when the thin film layers constituting the organic TFT, such as the organic semiconductor layer and the gate electrode, are laminated using the technique disclosed in JP-A-2004-87976, a base layer formation process and an exposure process for forming a lyophilic region and a liquid repellent region need to be performed whenever each thin film layer is formed. By repeating these processes, there arises a possibility that thin film layers previously formed are damaged or device characteristics are adversely affected. When a plastic substrate is used as a support substrate, the support substrate contracts due to heat when the number of times of performing the exposure process is larger, and there arises a possibility that the alignment accuracy of each thin film layer formed on the support substrate decreases in some cases. When laser light is emitted in place of the exposure using a photomask, the treatment time becomes very long. Moreover, fine patterns are difficult to form.
JP-A-2006-237477 discloses a method for forming a gate electrode using an ink jet method but does not disclose a method for laminating two or more thin film layers, such as not only a gate electrode but an organic semiconductor layer, using an ink jet method.